The subject invention is directed toward the coupling art. More specifically, the present invention is directed to an improved apparatus for swaging ferrules to the outer surface of elongated cylindrical members.
The invention is especially suited for use in swaging ferrules of tube fittings and will be described with particular reference thereto. However, it should be appreciated by those skilled in the art that the invention is capable of broader applications and could be used for attaching ferrules to many types of cylindrical members.
Tube or pipe fittings which employ one or more swaged ferrules on the periphery of a tube to make metal to metal seals at a joint are in widespread use. Experience has shown that the swaged ferrule type fittings with their metal to metal sealing surfaces are particularly effective in providing strong leak-tight joints. In swage type tube fittings, the grip of a swaged ferrule on the periphery of the tube is critical to the proper functioning of the fitting. Typically, the nose portion of the ferrule must be forced radially inward to achieve a good grip on the tube but without extensive tube deformation.
With fittings currently in use, the ferrules are typically swaged into sealing position by a manual tightening of a coupling nut which forces the nose portion of the ferrule against a camming mouth in an associated body member. The camming mouth deforms the nose radially inward into tight sealing engagement with the periphery of the tube or rod being coupled.
Power actuated ferrule swaging devices have been proposed in the prior art. Generally, these prior art devices have been somewhat complicated and cumbersome and have required die blocks and the like for engaging the ferrules and cooperating with a die member to perform the swaging operation. Generally, such power actuated swaging devices are used with large sized tubes or tubes formed of very hard material in order to apply the necessary swaging torque since for these applications it is difficult to get the necessary torque by a manual operation.
One problem with manually swaging ferrules on a conduit has been the difficulty of inexperienced operators in judging when adequate swaging has taken place. Another problem with a manual swaging of ferrules has been the length of time it takes to adequately swage a ferrule on a tube or pipe. This tends to be a problem when numerous swaging operations need to take place on a complicated conduit system of the type that is generally used in certain types of vehicles, such as airplanes.
While power actuated ferrule swaging devices might indicate when adequate swaging has taken place and might reduce the length of time the swaging operation takes, they have their own problems. For one, currently available swaging devices do not have an indicator means to let the operator know when a ferrule has been put in backwards or has been omitted entirely. Additionally, the conventional power actuated ferrule swaging devices utilize a coupling nut or female body portion of the fitting into which the swaged tube will be received to assist the swaging operation by threading the nut into engagement with a sleeve held on the tool. This operation is time consuming since the nut needs to be threaded onto the sleeve before the swaging operation and off the sleeve after the swaging operation.
Additionally, with the presently utilized power operated swaging tools which have an indicator arm cooperating with an indicator knob to form a latch mechanism, the knob needs to be readjusted for each swaging operation and this extra step adds to the length of the swaging operation. Also, normally a rubber hose or other flexible hose is connected between a pump mechanism and the swaging tool. Therefore, several additional pumping strokes are needed just to pressurize the fluid in the hose due to the normal expansion that a flexible hose undergoes.
Accordingly, it has been considered desirable to develop a new and improved swaging tool which would overcome the foregoing difficulties and others while providing better and more advantageous overall results.